Guard for pneumatic thread extractors



J1me 1940- R. G. TURNER GUARD FOR PNEUMATIC THREAD EXTRACTORS Filed April 1, 1939 Inventor Rmhawd C: Turner- Atmomey Patented June 11, 1940 UNITED STAT s.

,GUARD FOR PNEUMATIGTHREAD EXTRACTORS Richard G; Turner, Worcester, Mass, assignor to 'Crompton & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts Application April 1, 1939, Serial No. 265,471

12 Claims. (01. 139 256) .about in the tube to prevent it from becoming This invention relates to improvements in pneu out of the path of the shuttle.

matic thread extractors for weft replenishing looms and it isthe general objectof the invention to provide meansfto prevent improper entry of a weft thread into the intake mouth of the thread extractor. y

In my co-pending application Serial No. 190,637 I have set forth a pneumatic thread extractor employing a tube which is moved to a position adjacent to the thread of the outgoing bobbin on weft replenishing beats of the loom. In that application 1 a. partial vacuum is-created inithe tube during picking of the shuttle'so that the thread which has been cut in the shuttle box prior to picking can be drawn into the tube and I 'find that. with certain types of yarn there is a tendency for the thread to follow the shuttle at the time ofpicking and be whipped around the lower end of the extractor tube sufiiciently tightly to resist the sucking action'of the air. It is an important.ob-- ject of my present invention to provide the intake tube with a shield or guard so placed as to prevent the thread from becoming wrapped directly on the tube. j As the cut end of the thread leaves the shuttle box and approaches the extractor it may approach the latter with its free end pointed toward the intake mouth. If the end of the thread should enter the mouth a loop will be formedwhich may become entangled with the tube or some part thereof serving to .direct'the thread into the intakemouth. Such a loop would prevent the thread from entering the thread ex-. tractor and militate against operation of thelatter. It is another object of my present invention to provide a form of baflie adjacent to the intake mouth which will be located to deflect the end of the thread away from the mouthand therefore avoid the formation of loops.

In the aforesaid co-pending application Ishow a-tube which is cylindrical throughout its length so that its cross section is substantially uniform, thereby causing the column of v air to move through the tube with auniform rate of motion. I have I found thatimproved results attend the use of the tube the lower'end of which is reduced in' cross section and believe that such a construction insures a relatively high rate of air travel through the lower end of the tube to. exert an increased tractive force on the thread. Because of the varyingcross section of the tube the air in the uper part thereof above the reduced cross section is disturbed by eddy currents .or the like which agitate the thread and move the latter Fig/3isa front view too close to one side of the wall of thetube Where theair is moving at a relatively slow rate of speed.

In order therefore to insure a relatively high rate.

of .air motion immediately above the intake mouth and also to subject the thread when in the tube-- to vibrationresulting from pneumatic disturb: ance it is a further object. of my invention to reduce the lower end of the tube so that its cross section is less than that in the other part of the tube.

- ith appear as the description proceeds; my invention resides in the combination and arrangement of parts hereinafter described andset forth. i

these and other objects in view which will L In the accompanying drawing. wherein a con- 7 venient embodiment of my invention is set forth;

Fig. 1 is an elevationtaken from the center of the loom of certain parts associated with the extractor. tube forming the subject matter of mypresent invention,

end of the tube shown in Fig. 1 on an, enlarged scale,jy f of the structure shown in Fig. 2 looking in the direction of arrows 3, Fig. 2; Fig.4 is a horizontal section'oniline 4- -4 of Fig.3, 1

' Fig. 5 i's a diagrammatic plan view of a portion of theloom showing the shuttle box and shuttle therein'from which the weft thread extends to Fig. 6 is a diagrammatic front elevation indicating the manner in which the weft thread tends to'be Wrapped around and sucked into the intake mouth of a pneumatic thread extractor.

. Referring to Fig. 1,1 a'fixed support l0 onwhich isv pivoted .a carrier 7 I Ito be engaged by a resettingscrew [2 on the beats of the loom. By means of frictionmeans' designatedgenerally at 2| located between the support In and the carrier 'll the'latter. is normally held withthe tube I! raised, this po'sitioning being efiected by thefllay carried screw l2 on the backward stroke of .the lay, aftertransfer the cloth and suggesting-the relationship which g I ,my invention bears to the'threaiand have-shown a lay L and 4 On transferring beats of the loom the arm 20 descends to lower the rod Id and tube ll while the lay is in forward position or in a position to the right of that shown in Fig. 1.

In Fig. I show the shuttle S in dotted lines in the position it assumes at the time of transfer with the lay on front center position and the thread W leaving the shuttle box B and extending toward the fabric F along a line which extends diagonally rearwardly in front of the back of the box 22. The tube ii is so positioned that when lowered by the transferrer arm 26 it will lie behind the thread W and in front of the box back or reed line. As the lay moves rearwardly to the position indicated in full lines in Fig. 5 the thread W will move toward the lower end of the tube l I. When in the full line position shown in Fig. 5 the shuttle S is picked out of the box by a picker P. A thread cutter C acts'to cut the thread adjacent to the shuttle eye designated at E on transferring beats of the loom. That part of the thread W extending to the left of the cutter C, Fig. 5 will ordinarily be held between the shuttle and the binder 23 during the first part of the rearward sweep of the lay. At the time 'of picking, however, emergence of the shuttle. from the box will release the thread so that it can respond to the pneumatic attraction of the extractor. I arrange apparatus to create sub-atmospheric pressures in a tube 24 attached to the upper end of the tube 11 during the time that the shuttle S is being picked out of the shuttle box.

For further reference as to the construction and more detailed operation of those parts which position the tube IT and create sub-atmospheric pressures in the tube 24 reference may. be had to my aforesaid co-pending application, and for further reference to the thread cutter C attention may be called to Payne PatentNo. 1,881,920.

In Fig. 6 I have indicated diagrammatically the behavior of the thread W with respect to the lower end of the tube I1. As the shuttle is picked out of the box it will travel along the path behind the tube, and will be clear from Fig. 5. The thread however has been caught in the hook adjacent to the intake mouth of the extractor as will be described hereinafter, and that end of the thread lyingbetween the extractor tube and the shuttle box tends to move around the tube by a left hand motion as viewed in Fig. 5. The creation ofa partial vacuum in the tube 6? draws a part of the thread into the tube as shown at 30 in Fig. 6, and at times, depending upon atmospheric conditions along the path of shuttle travel, the thread will loop as at 3i and the end I 32 thereof will move to a position in proximity to the intake mouth of the tube. This does not happen on every transferring beat of the loom, and in fact for the greater part of the time the thread is drawn upwardly into the tube without having the end thereof approach closely enough to the intake to be attracted by the inrushing column of, air. I have noted on occasions however that the relation indicated in Fig. 6 does exist and it is to correct this condition that I have provided theguard or baliie to be described in detail hereinafter.

In carrying my present invention into effect I have provided a guard designated generally at G shown here as a strip of sheet metal bent in the general for-m of a triangle with substantially vertical walls. The guard has a flat vertical wall Q2 which may be substantially parallel to the box back 22, although its position can be varied angularly with respect to the box back by reason of the adjustable screw IS. The wall t2 extends from the tube toward the fabric F. Before the end 32 of the thread can start to move forwardly from a position to the left of the tube ll it must clear the wall 12, and in doing so is kept a considerable distance from the tube H.

In order to provide further assurance that the thread end 32 will not enter the mouth of the .cxtractor tube I extend another wall of the guard forwardly and diagonally as at 43, see Fig. This wall 43 is spaced from and lies a substantial distance in front of the tube ii to lie in the path of the thread end 32 should the latter whip around the left end of a wall t2 and be pointed toward the tube IT. This wall 43 gives further assurance that the thread end will be kept a safe distance from the tube IT.

The third wall 44 extends forwardly from the right end of wall 42 and may be secured to the front part of wall 43. As will be apparent from Fig. 4 this third wall is so placed as to constitute a baffle for the end of thread 32 should the latter succeed in passing around wall 42 and beyond the wall it. The tube therefore extends into a triangle of walls two of which are spaced sufiiciently from the tube to serve as a guard or bafile to prevent the thread from becoming wrapped on the tube l1 and also to deflect the end 32 of the weft end W away from the tube.

As shown in Fig. 2 the wall M is curved downwardly and rearwardly as at 50 and this wall together with wall 43 may then continue to move downwardly and rearwardly as at 58. The effect of the downward and rearward curve shown in Fig. 2 is to assist a thread which may be wrapped around the triangle of walls in a downward direction. It is to be understood that because of the pneumatic attraction of the thread the latter will tend to move down and the form of the guard shown in the drawing is such that the perimeter thereof measured horizontally gets less and less toward the lower end thereof. This construction facilitates the lowering of any thread which may be wrapped around all three walls of the guard.

Another feature of my invention relates to the form of the lower end of the tube El and as shown in Fig. 2 it will be seen that I have removed the rear or left part of the cylindrical tube l1 and closed the same by a plate 6!) which may be integral with the wall 42. The cross section of the lower end of the tube, as indicated in Fig. 4, may be semi-circular, but I do not wish to be limited to this particular form. The wall 60 and a portion of the wall 42, both of which are fastened to the reduced lower end of the tube from a column of substantially less cross section than that which exists above the wall 60, or in the upper part of the tube l1. As a result of this variation in cross section of the tube 51 eddy currents or the like are set up in the upper cylindrical part of the tube serving to disturb or vib-rate any threads therein to cause dislodgment thereof from the walls of the lower part of the tube and thereby move the thread into an active and rapidly moving part of a column of air which isascending within the tube H. The reduction of the lower end of tube H also'results in a relatively higher speed of air moving upwardly in the reduced lower end than would be the case if the tube were cylindrical throughout its length and there results an increased pneumatic tractive force on the thread in the lower part of the tube.

mouths and do not wish therefore to be limited to the particular type of mouth shown more particularly for instance in Figs. 2 and 3. A wire 55 secured to the wall 42 and extending downwardly along the tongue T reinforces the latter.

I believe the operation of my present invention will be apparent from the foregoing description, but I may add that continued experience shows that a guard formed as set forth herein is effec-- tive to prevent the thread from wrapping around the lower end of the tube and also serves to prevent the end 32 from entering directly into the intake mouth M in such a way as to form a loop 3|. It is to be understood of course that the thread 32 eventually enters the tube H by being drawn thereinto as the last part of the thread to enter the mouth end. Furthermore, the

guard forms a hollow housing into which the tube extends. Also, the guard has a generally downwardly tapered form constructed so that the perimeter of successively lower horizontal sections decrease, thereby offering no resistance but rather facilitating the downward sliding of any thread which may happen to be wrapped around the guard.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. An attachment for loom pneumatic thread extractor, said attachment comprising a tube one end of which has a smaller internal crosssection than the other end to cause eddy currents in air passing through the tube, and said tube having an intake mouth in said one end, and a thread guiding tongue to direct a thread to the opening.

2. An attachment for a loom pneumatic thread extractor comprising a cylindrical tube the lower end of which is reduced to have across-section which is part only of a circle, the lower end having an intake mouth, and a guide to direct the thread to the mouth.

3. An attachment for a loom pneumatic thread extractor, said attachment comprising a tube the lower end of which is of less cross-sectional area than the upper end and having a thread intake mouth therein, a thread guiding tongue projecting downwardly and forwardly from the intake'mouth, and a thread hook having an upw wardly opening thread pocket facing the intake ''-prevent a thread from being wrapped directly on to the tube.

mouth of the tube.

4. An attachment for a loom pneumatic thread extractor, said attachment comprising a tube the lower end of which is of less cross-sectional area than the upper end and having a thread intake mouth therein, a downwardly and forwardly extending tongue below the intake mouth, and a thread hook having a thread receiving packet which opens upwardly toward the opening of the intake mouth.

5. An attachment for a loom pneumatic thread extractor, said-attachment havin g'a tube with an intake mouth in the lower end thereof, a thread guiding tongue directed upwardly and rearwardly "toward the intake mouth, and a thread'guard carried by the tube and comprising a laterally extending wall projecting to'one side of the intake mouth to prevent the thread from becoming wrapped around the tube.

6. An attachment for a loom pneumatic thread;

extractor, said attachment having a tube with an .intake mouth in the lower end thereof, a

thread guiding tongue directed upwardly and rearwardly toward the intake mouth, and a thread guard comprising two walls substantially at rightangles with each other one of which extends forwardly and above the intake'mouth to assist in directing a thread in front of the attachment toward the tongue and intake mouth, and the other of which extends laterally beyond the intake mouth, said walls both acting to prevent a thread from being wrapped closely around the tube.

'7. An attachment for a loom pneumatic thread extractor, said attachment having a tube with an intake mouth in the lower end thereof, a thread guiding tongue directed upwardly and rearwardly toward the intake mouth, and a guard comprising a rear wall projecting laterally from one side of the-mouth and comprising also a second wall extending diagonally and forwardly in a direction away from the outer edge of the first wall, said walls preventing a thread from being wrapped around the tube.

8. An attachment for a loom pneumatic thread extractor, said attachment having a tube withan intake mouth in the lower end thereof, a thread guiding tongue. directed upwardly and rearwardly toward theintake mouth, a guard carried by the tube and located above the intake mouth and comprising three walls one of which. extends laterally beyond the intake mouth, the second of which extends forwardly from the tube, and the third of which connects the first tWo walls and is diagonally disposed relatively thereto, said walls preventing a thread end which is wh pped around them from; passing directly into the intake mouth.

9. Anattachment for a pneumatic thread extractor for a loom, said attachment comprising a tube having a thread inlet in the end thereof,

a tongue projecting diagonally in a vertical direction away from the inlet to direct a thread toward the latter, and means surrounding the tube to engage a thread which'is whipped around the tube and prevent said thread from being wrapped directly on to the tube.

10. An attachment for a pneumatic thread extractor for a loom, said attachment comprising a tube having a thread inlet mouth, a tongue projecting downwardly and forwardly from the mouth, a wall extending forwardly from the tube, and a second wall extending diagonally rearwardly from the first wall, said walls acting to mouth.

providing a wall located above the intake mouth and into which the tube projects to prevent a thread from being wrapped directly on to the tube.

RICHARD G. TURNER. 

